X-ray tube.



PATENTED OCT. 18, 1904.

C. H. R'MLLER.

.X-RAY TUBE.

APPLIOATION FILED HAR. 2a, 1904.

vN0 MODEL.

Ilfl QFunnm Inventor.'

I UNITED STATES Patented October 18, 1904.

PATENT CEEICE.

x-RAY TUBE.

SPECIFICATION forming part of Lett-ers Patent No. 772,667, dated October18, 1904.

ApplicaHo-*i filed March 23,1904.

To @ZZ whom, it may concern:

Be it-known that I, CARL HEINRICH FLORENZ MLLER, a subject of the GermanEmperor, and a resident of Hamburg, -in the German Empire, have inventedcertain new and useful Improvements in'vX-Ray Tubes, of which thefollowing is a specification.

, My invention relates to improvements in Roentgen tubes, and moreparticularly to means for adjusting and regulating the intensity of therays generated in and emanating from the tube. As is well known, thisobject may be accomplished more or less effectively by regulating thedegree of vacuum inY the tube; butI have found that the penetratingpower and volume of rays desired to be obtained from a tube can be mosteffectively controlled and regulated by varying the area of thereiiecting-surface of the cathode. In my present invention I have showna structure wherein this object can be accomplished, andI have alsofound that the two methods of regulation above referred to can becombined very readily and to great advantage, the result being a tubewhich is entirely under the control of the operator and one capable of averywide range of adjustment and utility.

One form of my invention is shown in the accompanying drawings, wherein-Figure l is a longitudinal section through a Roentgen tube in accordancewith this .invention, and Eig. 2 is a detached view of the adjustablecathode in another operative condition. i

Similar letters of reference are employed to designate like parts in thetwo figures.

The Roentgen tube a is provided in thel known manner with a principaland also a subsidiary anode b and c, respectively. The' fore portion ofthe cathode is composed of an inner concave mirror f' and an outerannular body f2, these parts formingI a large reflecting-surface. towardthe anticathode Z) when the inner hollow mirror is situated in theposition shown in Fig. l-that is to say, inthe annular body.`

The annular body f2 is fixed upon atube la, of insulatingmaterial, whichsurrounds the metallic sleeve 7i and bears upon it. The piston-rod g,carrying the concave mirror 7', is

Serial No. 199,649. (No model.)

displaceably mounted in the sleeve L. The annular body f2 is thereforeinsulated from the conductor z' t by means of the insulating-tube in,and the current can only enter the annular body when the concave mirrorf is in contact with the same-that is to say, when it occupies theposition shown in Fig. 1. In this case the parts act as a single cathodeof large size. Y On the other hand, when theinner conj cave mirror ispushed out-that is to say, when it is removed from contact with theannular body f2, Eig. 2-only the concave mirror f is operative, becausetheannular body f2 is then without current.

When the parts of the cathode are in the position shown in Fig. l, thereflecting-surface is of comparatively large size and rays in largevolume are emitted. When the parts are in the position shown in Eig. 2,the effectvive reflecting-surface is greatly reduced and the raysemittedare correspondingly reduced. It will also be seen th at by makingthe cathodereflector movable its distance from the anticathode may beregulated, and in this manner it is possible to so arrange the partsthat the point of focus corresponds with the surface of the anticathode,and it willbe understood that `the intensity of the rays may in thismanner be regulated to some extent.

' rIhe displacementof the concave mirror f' or of the piston g,Vcarrying it, in the sleeve t, is effected by suitably inclining andshaking the Roentgen tube. v The piston g is therefore mounted in thesleeve /L with such friction that it will remain in the position inwhich it has been set. For the purpose of liner adjustment of its degreeof hardness the Roentgen tube is also preferably provided with anauxiliaryrcathode d, which vis arranged in a chamber e, fused directlyon the sphere a, this cathode CZ carrying on its inner end agas-producing body Z (such as a disk of mica, for example) and servingin the known manner for rendering the tube sof-ter. In the same vacuousspace with the vmain cathode I also arrange asecondary terminal, whichconsists of a-platinum wire or some other similar substance and v whichwhen heated by the passage of an electric current or otherwise has theproperty of absorbing the gaseous matter within the tube,

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thereby enabling the operator to raise the vacuum and harden the tubewhen the same may be necessary. The arrangement of the twolast-described regulating devices in chambers Which are quite separateone from the other and which proceed directly from the sphere ct,contrary to what has hitherto been the usual arrangement of them in acommon chamber or in a chamber divided by a partition, presents theadvantage that, iirst, the tube as a Whole is reduced in volume, and,second, the rays proceeding' from one electrode are not able toinfluence the substance of the other, which would prejudicially affectthe regulation sought to be attained.

Having fully described my invention, what I claim, and desire to secureby Letters Patent, is-

l. A vacuum-tube having anode and cathode terminals, a primary regulatorfor varying the intensity of the cathode rays and a secondary regulatorfor controlling the degree of vacuum of the said tube, substantially asdescribed.

2. A vacuum-tube having anode and cathode terminals located therein, andmeans for varying the reflecting-surface of the cathode-terminal,whereby the intensity of the rays is controlled and regulated,substantially as described.

3. A vacuum-tube having anode and cathode terminals located therein,said cathode being provided with a variable reliecting-surface forregulating the intensity of the rays, and a secondary regulatorcomprising means for varying the degree of Vacuum in the tube,substantially as described.

4. A vacuum-tube having anode and cathode terminals located therein,said cathode-terminal comprising a plurality or' separablereflecting-surfaces insulated from each other when separated,substantially as described.

5. In a vacuum-tube for generating X-rays, a cathode-terminal comprisinga reiiectingsurface composed of a plurality of concentric separableparts, said parts being electrically insulated one from another when outof physical contact, substantially as described.

6. A regulator for varying' the intensity oi' rays in a Vacuum-tube,comprising a cathodeterminal having a reiecting-surface composed of aplurality of parts insulated from one another When out of contact, aportion of said reiecting-surface being movable so as to vary thedistance between it and the anticathode in the tube, substantially asdescribed.

7. In a vacuum-tube, the combination of a set of terminals located insaid tube, one of said terminals having a variable reflectingsurface forchanging the intensity ol the rays issuing from the tube, substantiallyas described. U 8. In a vacuum-tube, the combination oi a set ofterminals located in said tube, one of said terminals having areflecting-snriace, a portion of which may be rendered inoperative tochange the intensity of the rays issuing from the tube, substantially asdescribed.

9. In a vacuum-tube. the combination ol a set of terminals located insaid tube, one of said terminals having a fixed member and an adjustablemember coacting therewith to vary the intensity oi the rays issuing fromthe tube, substantially as described.

lO. In a vacuum-tube, the combination of a set of terminals located insaid tube, one ol said terminals having a lixed member in circuit andcoacting with an adjustable member, and means for disconnecting andrendering said fixed member inoperative to vary the intensity of therays issuing from the tube, substantially as described.

11. In a vacuum-tube, the combination ol a set of terminals located insaid tube, one terminal comprising an annular member normally in circuitand coacting with a central adjustable member, and means for adjustingsaid central member and disconnecting said annular member to vary theintensity oi the rays issuing from the tube` substantially as described.

l2. In a vacuum-tube, thc combination of a set oil terminals located insaid tube, one terminal comprising an annular member mounted on aninsulated support, and a central adjustable member normally registeringand coacting with said annular member and slidably adjustable to varythe intensity of the rays issuing from the tube, substantially asdescribed.

CARL llElNRlCll FLORENZ MLLER.

lVitnesses:

MAX KAEMPFF, E. H. L. MUMMENUOFF.

